Obama and Merkel don't own their countries like Putin owns Russia. Putin is a near-dictator, and the others aren't.
People might differ. For me, Obama is more of a dictator than Putin.
80% support for Putin? Well. I guess it's easy to get support when you don't have a problem killing your opponents or those who criticize you.
People will be having their own priorities. Ordinary Russians are thankful to Putin, for significantly improving their living conditions over the years. Also, most of the opposition figures in Russia are having an image problem. And who is killing their political opponents? Are you talking about the future-POTUS Hillary Clinton, who has murdered more than two dozen of her political opponents? Remember Vince Foster?